Thirlwall Inquiry: Timeline

Verbatim (Inquiry team page): 'On 4 September 2023 she was appointed to chair the inquiry into the events at the Countess of Chester hospital by the Secretary of State for Health and Social Care.' Corroborated by the same-day news post (see announced row).

Verbatim: 'On 4 September 2023, Lady Justice Thirlwall was announced in Parliament by the Secretary of State for Health and Social Care as the chair to the statutory inquiry that would examine events at the Countess of Chester Hospital and their implications following the trial, and subsequent convictions, of former neonatal nurse Lucy Letby.' Same event/date as chair_appointed below.

Lady Justice Thirlwall appointed as Chair of the Inquiry.

Verbatim: 'The Government published the Terms of Reference to the Thirlwall Inquiry on 19 October 2023.' Full text at thirlwall.public-inquiry.uk/about/terms-of-reference/ ; PDF at thirlwall.public-inquiry.uk/document/terms-of-reference/ . No subsequent amendment found.

Health Secretary Steve Barclay announced a statutory inquiry following Lucy Letby's conviction.

Verbatim (Preliminary Hearing transcript, 16 May 2024, p.6): 'Material was first provided to the Inquiry by Cheshire Police in the week of 20 November 2023, just one month after the Inquiry was established.' Date given here is the Monday of that stated week; source does not give a single exact day. Same transcript also notes Rule 9 evidence requests began even earlier: 'Within a few days of publication of the terms of reference, the first letter making a request for evidence, known as a Rule 9 request, was issued to the Countess of Chester Hospital. Within a month, twenty Rule 9 requests had been made' (i.e. from late Oct 2023).

Rolling process, not a single-date event. This is the earliest confirmation found that designations had begun, verbatim: 'The Chair has already designated a number of parents of babies named on the indictment as Core Participants. Eight applications have also been received from organisations within the healthcare sector. The Chair now invites applications for Core Participant status from any other interested organisation or individuals.' Designation activity continued at least to 2 Oct 2024 (ruling on Lucy Letby's own, later CP application). Current roster 'correct as at 22 September 2025' lists 10 CP table entries -- see thirlwall_figures.tsv core_participants_total and thirlwall_instruments.tsv cp_designation_ruling rows.

Terms of Reference set to examine events at Countess of Chester Hospital.

Verbatim (Witness Timetable page): 'From 16 September 2024 to 17 January 2025, the Inquiry heard oral evidence from witnesses relating to Parts A, B and C of the Terms of Reference.' The news post 'Inquiry finishes hearing oral evidence' (published 20 Jan 2025, thirlwall.public-inquiry.uk/2025/01/20/inquiry-finishes-hearing-oral-evidence/) states: 'Since hearings began on 10th September 2024, the Inquiry has sat for 59 days and heard evidence from 133 witnesses' -- see thirlwall_figures.tsv sitting_days_stated / witnesses_oral. A further single-witness 'Further Evidential Hearing' was held later, on Monday 24 February 2025 (Dr Susan Gilby, former CEO of Countess of Chester Hospital), announced at thirlwall.public-inquiry.uk/2025/02/18/thirlwall-inquiry-to-hear-additional-evidence-on-monday-24-february-2025/ -- not included in the 17 Jan date or the 59-day/133-witness count above.

PLANNED date, not independently confirmed as an exact start date. Verbatim (22 May 2025 'Update on Final Report'): 'The Chair, Lady Justice Thirlwall, is expected to send out warning letters from September 2025 and the final report will be completed by the end of November.' The 27 Feb 2026 update (thirlwall.public-inquiry.uk/2026/02/27/february-2026-update-on-final-report/) confirms warning letters were an active, ongoing process by that date, verbatim: 'the Inquiry will continue its business as usual, which includes uploading documents to the website, sending warning letters to those who may be subject to explicit or significant criticism, and working with publishers.' Date recorded here (2025-09-01) is the first day of the month named as the expected start, not a stated exact day.

The Inquiry stated the final report will be published at the earliest practical date, after the summer recess of Parliament.